Mitochondria and chloroplasts display similarities with bacteria that led to the endosymbiont theory. This theory states that an early ancestor of eukaryotic cells engulfed an oxygen-using non-photosynthetic prokaryotic cell. Eventually, the engulfed cell formed a relationship with the host cell in which it was enclosed, becoming an endosymbiont, a cell living within another cell. Indeed, over the course of evolution, the host cell and its endosymbiont merged into a single organism, a eukaryotic cell with a mitochondrion. At least one of these cells may have then taken up a photosynthetic prokaryote, becoming the ancestor of eukaryotic cells that contain chloroplasts.
| Game | Time | WPM | Accuracy |
|---|---|---|---|
| 43392 | 2018-10-08 11:18:58 | 121.40 | 99% |
| 41828 | 2018-08-11 17:41:14 | 100.44 | 97% |
| 38366 | 2018-05-16 17:23:20 | 118.76 | 98% |
| 36176 | 2018-03-31 08:11:53 | 116.95 | 99% |
| 34632 | 2018-02-16 13:39:06 | 110.58 | 97% |
| 34230 | 2018-02-09 19:55:19 | 116.64 | 99% |
| 31046 | 2017-12-09 14:38:50 | 104.00 | 97% |
| 28851 | 2017-11-06 12:45:35 | 116.27 | 99% |
| 28655 | 2017-11-05 09:48:35 | 102.92 | 98% |